Touchwood
Free Member
- Aug 23, 2011
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- 733
- Funster No
- 17,874
- MH
- Compass Avantgarde 140
- Exp
- 5 years and learning
Reading February's Practical Motorhome, I came across the following from "Diamond Dave" in the technical advice section.
"Take water tanks, for example. They're often underslung and if you're driving at 60mph, there's going to be a 60mph gale blowing along the underside of your 'van. This will create a significant wind chill factor and if the ambient temperature is low - say, around 5 deg. C - then the tanks and pipework will be subjected to a sub-zero blast that can cause water to freeze.
The solution is to insulate the tanks and pipework:...."
I'm don't wish to impugn Diamond Dave's technical expertise in other areas, but this is nonsense, and a commonly held misconception. Wind chill factor only affects bodies with their own heat source which keeps them above the air temperature (like warm blooded mammals such as you or I)
It is true that the air velocity will cause a greater rate of heat loss, but only until the temperature of the water tank has dropped to that of the surrounding air. Once the temperatures are equal, there is no temperature gradient and heat will cease to flow.
There may well be other perfectly valid reasons for insulating your underslung tanks and pipework, but wind chill isn't one of them.
"Take water tanks, for example. They're often underslung and if you're driving at 60mph, there's going to be a 60mph gale blowing along the underside of your 'van. This will create a significant wind chill factor and if the ambient temperature is low - say, around 5 deg. C - then the tanks and pipework will be subjected to a sub-zero blast that can cause water to freeze.
The solution is to insulate the tanks and pipework:...."
I'm don't wish to impugn Diamond Dave's technical expertise in other areas, but this is nonsense, and a commonly held misconception. Wind chill factor only affects bodies with their own heat source which keeps them above the air temperature (like warm blooded mammals such as you or I)
It is true that the air velocity will cause a greater rate of heat loss, but only until the temperature of the water tank has dropped to that of the surrounding air. Once the temperatures are equal, there is no temperature gradient and heat will cease to flow.
There may well be other perfectly valid reasons for insulating your underslung tanks and pipework, but wind chill isn't one of them.